Chirpoi

Russia

46.532°N, 150.871°E; summit elev. 742 m

All times are local (unless otherwise noted)

SVERT reported that a thermal anomaly over Snow, a volcano of Chirpoi, was detected in satellite images during 19-20 February. Cloud cover obscured views on the other days during 17-24 February. The Aviation Color Code remained at Yellow.

Geologic Background. Chirpoi, a small island lying between the larger islands of Simushir and Urup, contains a half dozen volcanic edifices constructed within an 8-9 km wide, partially submerged caldera. The southern rim of the caldera is exposed on nearby Brat Chirpoev Island. The symmetrical Cherny volcano, which forms the central cone of the island, erupted twice during the 18th and 19th centuries. The youngest volcano, Snow, originated between 1770 and 1810. It is composed almost entirely of lava flows, many of which have reached the sea on the southern coast. No historical eruptions are known from Brat Chirpoev, but its youthful morphology suggests recent strombolian activity.